Tension adjusting device



April 1939- c. s. ANDERSEN 2,153,705

TENSION ADJUSTING DEVICE Filed Sept. 14, 1937 22 19 FIG-2 l5b l5 I54 lficu 3 4% (a O O0 OO O O INVENTOR CHRISTIAN s. ANDERSEN BY i5!) .fl 2

ATTO NEYS Patented Apr. 11, 1939 UNITED STATES TENSION ADJUSTING DEVICE Christian S. Andersen,

Warren, Pa., assignor to Pennsylvania Furnace & Iron (30., Warren, Pa., a corporation of Pennsylvania Application September 14, 1937, Serial No. 163,786

1 Claim.

This invention relates to improvements in tension adjusting devices for endless motion transmitting members such as belt and chain drives and the like.

An object of the present invention is to provide an adjustable support for a pulley, sprocket or the like, the support being resiliently flexible around an axis normal to the plane of the endless motion transmitting member and being held rigidly in various adjusted positions by a flexible securing member. It results from such construction that by utilizing a flexible support and a flexible securing member for holding the support in various positions, adjustability is secured while at the same time all of the parts are in fixed and substantially rigid connection with each other and noiseless in operation.

Other novel features of my invention will be apparent from the accompanying drawing and specification and the essential features will be summarized in the claim.

In the drawing, Fig. 1 is an elevational view of a belt drive equipped with my improved tensionadjusting device; Fig. 2 is an enlarged detail view of a portion of Fig. 1; Fig. 3 is a plan view of the motor supporting plate of Figs. 1 and 2; while Fig. 4 is a view of one of the adjusting bolts of Figs. 1 and 2.

I have shown my improved tension adjusting device in combination with a motor Ill having a pulley I I which is connected by endless belt I2 with a pulley I3 of a blower I4. It will be understood, however, that the device is applicable to other drives including chains and sprockets and that the adjustability may be in respect to either a driving or driven rotatable member.

The motor I is mounted on a rigid plate I5 which may be provided with a plurality of openings I5u permitting the mounting of the motor in various positions on the plate. At its edge nearer the pulley I3 the plate I5 is provided with a flexible support I6. This support as shown is an angular plate having one end rigidly secured at I! to a member IB which is welded between the base I9 and the blower I4 so as to form a rigid support at the point IT. The member I6 is secured at its other end 20 to the plate I5. It will be understood that the member I6 may be metal, fiber or the like. It may be a sheet member or separate straps or bars spaced along the edge of plate I5. Plate I5 and member I6 might be integral to give the same result. The requisite connection is one which is the equivalent of a flexible steel plate, flat spring or the like connecting the plate I5 to the rigid supporting member I8 for bending or swinging movement of said plate as though it were hinged on an axis normal to the plane of the endless member l2, or parallel to the shaft of motor ID.

The support I5 by means of the flexible member I6 is movable to various positions as indicated in full lines and dot-dash lines in Fig. 2. This produces a movement of the motor shaft along substantially the path A, Fig. 1, which is substantially an are about the point B. For holding the support in various adjusted positions the free or outer end of the support I5 is held by a flexible securing member which is rigidly fastened to the support I5 at one end and rigidly fastened to the base or other fixed member at its other end. The connection shown comprises one or more bolts 2I having their lower ends fiattened as at Zia to provide a flexibility in this portion of the bolt. Each bolt is secured at its lower edge as shown at 22 to the base I9 or other rigid support. The fastening means shown is welding. The bolts pass through slotted openings I51) in the plate I5. Nuts 23 threaded on the bolt above and below plate I5 hold the plate in various adjusted positions along the bolt. As viewed in Fig. 2, it will be seen that the bolts 2| flex about the portions 2 la to permit adjustment of the motor in various positions about the point B, but in every such position the bolts 2| are rigidly secured to the plate I5 at one end and the bolts are rigidly secured to a fixed support at the other end.

By the use of my improved structure herein disclosed, it is possible to obtain a very fine adjustment of belt tension which is not disturbed by a motor rotating at high speeds. There are no springs having a free play which would give a period of vibration to the driving or driven equipment and there are no parts to slip out of adjustment or to wear, such as is commonly found in adjusting devices of similar character. It results from the use of such a tensioning device that in equipment such as air conditioners a silent drive is provided for blowers, fans and the like, thus preventing the objectionable noise which often occurs at these points.

By the use of the term plate in the specification and claim I mean to include metal, fiber and the like, whether strictly of plate form or in the form of straps and bars.

In the specification and claim, by the use of the term endless belt I mean to include all endless flexible drives requiring a tension adjustment from time to time.

What I claim is:

Take-up means for a belt in driving relation with a shaft, comprising a base, support means for said shaft supported on said base and adjustable to various positions angularly about an axis parallel to said shaft, a bolt having one of its ends made substantially integral with said base as by welding, means for adjustably and rigidly connecting the other end of said bolt with said support means, and said bolt having a portion sufficiently flexible to permit it to accommodate itself to adjustment of said support means.

CHRISTIAN S. ANDERSEN. 

